Neck
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SPPSPP: Spatial Pyramid Pooling

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modified PANPAN: Path Aggregation Network


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Reference- https://github.com/AlexeyAB/darknet/wiki/CFG-Parameters-in-the-different-layers
- YOLOv4: Optimal Speed and Accuracy of Object Detection
SPP: Spatial Pyramid Pooling
PAN: Path Aggregation Network